A method of fabricating a diffractive structure with varying diffractive element depth includes providing a shadow mask having a first region with a first aperture dimension to aperture periodicity ratio and a second region with a second aperture dimension to aperture periodicity ratio less than the first aperture dimension to aperture periodicity ratio. The method also includes positioning the shadow mask adjacent a substrate. The substrate comprises an etch mask corresponding to the diffractive structure. The method further includes exposing the substrate to an etchant, etching the substrate to form diffractive elements adjacent the first region having a first depth, and etching the substrate to form diffractive elements adjacent the second region having a second depth less than the first depth.